docs: def clean(ctx, docs=False, bytecode=False, extra=''):
      '''Cleanup all build artifacts'''
      patterns = ['build', 'dist', 'cover', 'docs/_build', '**/*.pyc', '*.egg-info', '.tox']
      for pattern in patterns:
          print('Removing {0}'.format(pattern))
          with ctx.cd(ROOT):
              ctx.run('rm -rf {0}'.format(pattern))